Communications devices mounted on airborne platforms transmit and receive signals using antennas mounted on the platforms. These signals can be transmitted on a variety of communication links to satellites, ground equipment, or communications devices on other platforms. Military satellite communications terminals typically rely on the gain and directionality associated with a steerable dish antenna to receive and transmit signals to an associated satellite. When such terminals are mounted on aircraft, developing the desired connectivity gives rise to the challenge of equipping the aircraft with compatible antenna functionality given the limited space available in most military aircraft.
An array of conformal antenna elements mounted in the airframe of an aircraft has been proposed to provide the required antenna functionality. Beamforming can be used to control the orientation and shape of the antenna pattern. Conventional open loop beamforming requires continuously updated knowledge of the satellite signal angle-of-arrival (AOA) as the aircraft maneuvers, as well as precision calibration of array-element location and phase-weighting control. It would be desirable to eliminate the need to determine the angle-of-arrival of incoming radio frequency signals.
There is a need for an antenna system that enables full-coverage of the desired connectivity between radio frequency devices in an aircraft, or other platform, and remotely located communications devices.